A complete environmental monitoring platform: ESP32 with DHT22 sensor running FreeRTOS firmware, publishing over MQTT to a Dockerised backend stack of Mosquitto, InfluxDB, and Grafana for real-time dashboards.
This platform demonstrates a full IoT monitoring stack built entirely from scratch using ESP-IDF — Espressif's production firmware framework — rather than higher-level Arduino abstractions. FreeRTOS tasks handle sensor reading, MQTT publishing, and watchdog operations as concurrent, loosely-coupled processes.
The backend is fully containerised with Docker Compose. Data flows from the ESP32 every five seconds into a Mosquitto MQTT broker, is consumed by a Python subscriber, written to InfluxDB, and visualised in Grafana dashboards that persist across restarts.
| COMPONENT | DETAIL |
|---|---|
| Microcontroller | ESP32-S3 DevKitC-1 |
| Sensor | DHT22 — temperature/humidity (−40°C to 80°C) |
| Firmware framework | ESP-IDF v5.5.2 with CMake build |
| Publish interval | Every 5 seconds |
| MQTT topics | esp32/dht/temperature, esp32/dht/humidity |